The present disclosure relates to a mount adapter and an imaging device.
Although digital single-lens reflex cameras have widely spread rapidly in recent years, they have not been able to meet a request for further reduction in size and weight of the body. This is considered as inevitable for a digital single-lens reflex camera to put a reflex mirror that switches an optical imaging path and an optical path for the finder and a pentaprism that guides a subject image to the finder (OVF: optical view finder) in the camera body.
With that, by being provided with an electric view finder (EVF) instead of an OVF, mirrorless digital single-lens cameras, which intend reduction in size and weight by eliminating the reflex mirror, have appeared. However, a sub-mirror that guides an incident light to a focus detection unit is eliminated from such a mirrorless digital single-lens camera as well as the reflex mirror, thereby not being able to carry out focus detection of a phase difference detection system by the camera main body.
Since a mirrorless digital single-lens camera has a shortened flange focal length compared to that of a digital single-lens reflex camera, interchangeable lenses used to be mountable to a digital single-lens reflex camera are difficult to be used on their own. With that, in order to effectively utilize the interchangeable lens resources in the past, an interchangeable lens for a digital single-lens reflex camera is mountable to a mirrorless digital single-lens camera by being mediated by a mount adapter.
Then, in order to make an interchangeable lens compliant with the phase difference detection system mountable, there is proposed an imaging device having the mount adapter that is provided with a focus detection unit of a phase difference detection system (for example, refer to International Publication No. 2008/099605).